With the rapid increase of packet-based traffic due to the acceleration of Internet Protocol (IP) for communication services, the introduction of a router network using routers for the purpose of efficiently accommodating such traffic is in progress. A representative example of a router network is disclosed in Patent Document 1. However, because the cost of the router network is high, the introduction of a network configured to cut through a router using a lower layer switch (for example, a multi-protocol label switch-transport profile (MPLS-TP)) for cost reduction is also in progress.
A network configuration including a router and a transmission device of the related art is illustrated in FIG. 7. The network of the related art includes routers 710-1 to 710-4 and transmission devices 720-1 to 720-4.
Data paths 730 to 735 are assumed to be set up in advance between the transmission devices 720-1 to 720-4, and the routers 710-1 to 710-4 are connected in a star shape via the data paths 730 to 735. A description will be given under the assumption that two arbitrary routers among the routers 710-1 to 710-4 all have an adjacent relation.
Because the routers 710-1 to 710-4 construct a data packet transfer route before data packet transfer, signaling circuits 711-1 to 711-4 start up a signaling protocol. The signaling circuits 711-1 to 711-4 transmit signaling information including IP address information (routing information) that they are capable of transferring to adjacent routers as signaling packets to the connected transmission devices 720-1 to 720-4 via switches 713-1 to 713-4. Upon packet delivery, the switches 713-1 to 713-4 assign medium access control (MAC) addresses of the destination adjacent routers 710-1 to 710-4 as transmission destination MAC addresses.
The transmission devices 720-1 to 720-4 refer to a transmission destination MAC address of an input signaling packet and select one of data transfer paths 730 to 735 corresponding to the transmission destination MAC addresses from their MAC-path mappers 721-1 to 721-4. After predetermined frame conversion has been performed in the switches 722-1 to 722-4, frame conversion results are transferred to the desired data paths 730 to 735.
After predetermined frame conversions have been performed on data from the data paths 730 to 735 in the switches 722-1 to 722-4, the transmission devices 720-1 to 720-4 extract packets and transfer the extracted packets to the routers 710-1 to 710-4 according to the MAC addresses of the packets.
The signaling circuits 711-1 to 711-4 of the routers 710-1 to 710-4 receiving signaling protocols from the transmission devices 720-1 to 720-4 construct relations between transmission destination IP addresses and the next transfer routers from routing information.
For example, when the router 710-1 receives the routing information capable of being transferred when one higher-order byte of an IP address from the router 710-2 is 0 to 100, the router 710-1 recognizes the next transfer destination router as the router 710-2 when one higher-order byte of a transmission destination IP address of the received data packet is 0 to 100.
Recognition results are registered in the routing tables 712-1 to 712-3. In the routing tables 712-1 to 712-3, output port information for a transfer destination IP address and a MAC address of the next transfer destination router are registered.
Thus, data packet transfer routes between the routers 710-1 to 710-3 are established before a data packet transfer.
Next, the data packet transfer will be described. It is assumed that a packet of a transmission destination IP address 10.1.1.1 is input from the router 710-1 and an output port 701 and a MAC address #710-2 of the next transfer destination router 710-2 are registered in the routing table 712-1 when one higher-order byte of the IP address is 0 to 100.
The data packet is input to the switch 713 of the router 710-1.
The switch 713 refers to the routing table 712-1 corresponding to the transmission destination IP address of the data packet and acquires information about the output port 701 and the MAC address #710-2 to be added. Thereafter, the MAC address #710-2 is added to the data packet and the data packet is output from the output port 701.
Upon receiving the data packet, the transmission device 720-1 refers to its transmission destination MAC address as in the signaling packet and selects the data transfer path 730 corresponding to the transmission destination MAC address #720-2 from its own MAC-path mapper 721-1. After the predetermined frame conversion has been performed in the switch 722-1, the frame conversion result is transferred to the desired data path 730.
After the transmission device 720-2 performs predetermined frame conversion on data from the data path 730 in the switch 722-2 and extracts a data packet, the data packet is transferred to the router 710-2 according to a MAC address of the data packet.
By means of the above, the data packet can be transmitted in the network of the related art including the router and the transmission device.